Select columns in the dialog for adding members to an item list is not working properly

[Nicklas Nordborg]

1. Go to the dialog for adding members to an item list: "Item list -> Members -> Add" dialog
2. Right-click somewhere on the row with column titles.

Normally, a menu is displayed with a list of all possible columns. In the popup it is possible to select which columns that are visible or hidden.

However, in this dialog the menu is not displayed correctly. It is positioned to the far left edge (it is expected to be positioned near the current mouse position), the background is transparent and it is partly hidden behind some elements.

The workaround is to use the "Columns..." button which opens a new window.